The R package commecometrics provides an accessible, open-access framework for modelling trait–environment relationships using community-level trait data from modern and ancient species. Ecometrics links the trait distributions of communities to their local environmental variables, enabling the reconstruction of past conditions and the prediction of community responses under future climate change. Existing tools for functional trait analysis often lack palaeontological integration or are limited to specific taxa. commecometrics addresses these gaps by offering a suite of functions to summarise trait distributions, construct ecometric models, visualise trait–environment relationships, assess model robustness and reconstruct environmental conditions. The package is designed for broad applicability across ecological and palaeoecological studies and includes tools for trait-based biodiversity analysis beyond ecometrics. Through a worked example using carnassial tooth relative blade length (RBL) in carnivoran mammals, we demonstrate the package’s capabilities for analysing trait–environment dynamics across space and time.